Bomb slip, towing gear, and analogous releasable attachments



July 22, 1952 Filed July 30, 1947 R. K. PIERSON ET AL 2,604,353

BOMB SLIP, TOWING GEAR, AND ANALOGOUS RELEASABLE ATTACHMENTS July 22,1952 R. K. Pu-:RsoN ETAL 2,604,353

BOMB SLIP, TOWING GEAR, AND ANALOGOUS RELEASABLE ATTCHMENTS Filed July50, 1947 2 SHEETS--SHEET 2 .rma/en TOR Patented July 22, 1952 "Freni" itFF i-C BOMB SHPITWNG GEAR. ANDANAL GOU's RELEAsABLE ATTACHMENTS-Reginaldirshaw .Pierson land Reginald Arthur Firman,

"Weybdg'e, England, assignors to VickersLArmstrongs Limited, London,England VmmlieatmhjJuly 30, 1947,"Ser`ial No. `*764,798 In 'GreatBritain December 22, 1941 `Section 1,- Public Law 696, August v8,1946Patent expires December 22., 1961 A 1 Claim.

The invention has reference t releas'able attachments for usefinconjunction with objects such as bombs, `mail Abags, .supply containersor -li-ke articles to .be dropped ffrom aircraft, or for use in towingoperations, and in other analogous circumstances, such attachments beingof the type comprising apair of load-engagin'gpvoted jaws which are heldengaged by the presence of a .movable stop between opposed bearing faceson cooperating .parts of saidjaws, 'and in whichth'e arrangement issuchthat the load vitself vreacts to impose forces tending todisengageYthe jaws and to eject said stop, locking mechanism Aimposing arestraining force on said stopin a direction opposed to said ejectiveforce, and't'rp- .mechanism for releasing the `stop to permitdisengagement Aof therload. In some known forms of attach-ment for thesepurposes the mechanism Ihas vbeenarranged in such manner that .the forcenecessary to be applied to release the load, as when dropping va bomb ordisengaging'a towed object -or craft, is a function of the load to be.released, this eiTect being attained by arranging -for the load toexert such a force upon thelook- .ing mechanism that the latteriseither` heldin .a neutral position or `subjected. to a slight.restraining action, thus preventing the .inadvertent v.release oftheloadfe. g. through vibration. Where toggle mechanismshave been employedto ,transinit the unlocking lforce they 'are usually .arranged to workover a dead centre .between .the locked and unlocked positions, -so that4it -is .neces- -sary to apply lsuiiicient power to operate themlthrough the dead centre position to unlock the attachment.Theres-istance to the unlocking operation due y.to friction alone isvery considerable 'land where it is necessary Vto raise or wind in the:load 'slightly to permit the attachment to be 'released the 'operationcan only .be .performed Vxtl'ith-tfh-e assistance offa certain degree ofpower.

object 'of the present inventionis the provision Pof an improved -formof Yreleasable -atmehment of the said type for use in the circum-'st'ances referred fto, wherein the power requisite 'to '.'Iretainthefattachment in-engaged condition and'to factuate the mechanism forreleasing the attachment willbe substantially less than that required inknown forms of attachment, and which will possess .certain additionaladvantages which are apparent from the following ldescription.

lfin a releasa'ble'attachment of this type accordance with the presentinvention, thefjaws -arezs'o narranged that the .forces due tothe loadacting thereonare for the greater part .balanced '2 by opposed reactionsin the vjaws through the stop, "but fthe bearing faces o'f the'jaw-parts'between which the 'stop is held are inclined 'to each otherat anang'l'e Suchjas will, in'norm'al working cmditions, Vir'np'osfeaslight 4ejectve force ohsaid s op.

Thema-nner 'which the invention is carried `int'o effect is hereinafterdescribed withreference to the accompanying-drawings, which illustrateby -wayofexamme 'e re1eassb1e attachment een-- "structed `in'accorda-nce with the invention, and which is suitable for'fus withbombs and'ot'her :articles to 'be dropped 'frein 'aircraft `in night. In'the drawings, Fig. 1 'is' a general elevation of the attachment, Figs.2 'and `3 are longitudinal sec- 'tions thereof .showing the V'respectingpositions of the component 'parts (a) lwhen supporting a leed and (b)when'the load has been dropped. Fig. 4 *"a fragmentary detail view insection, 'showing the manner in 'which the attachment is locked 'inA'the vload-supporti'ng position when it 'is re*- ei'red ite Vpreventthe attachment 'from being "released, ahdFig. '5 Vi's an end view 'ofthe sepaiable portion of the attachment, showing the electrica conte-etsthereon. A

"Referring to Figs. 1 to 5, it will b'e seen that 'the device thereiuustreted comprises a housing lwhich capable of being xed totheaircraft and .a slip I 6"'whi'c'h 'is shaped so as to be received ilto aCavity `5I in the hO'l'lSig `5 Whenhoisted into piace by means :e: 'ecable 'Il 'passing under .a Vpulley I8'. When 'the "slip reaches theposition shown in Fig. '2, 't't'ing closely within the housing,it isconveniently engaged byspring-actuated .retaining .jaws of which one isindicated in Fig. 1.at I 9, in Ythe manner described in Briti'sh Patentil'aecifieationNo. 497,009.. AThe means by which the slip can`bereleas'ed vfrom 'thehou'sng vare pref.- erably similar to `thosevdescribed 'in said British A'Specification No. 497,009, consisting of asliding wedge20 capable ofbeing moved by 'operation'of a cable 2|between Athe jaws'lLso as to disengage them from the vjaw-receivingslo'ts '22 of the slip, against the v.pressureo'f a spring `2`3.

The attachment Vfor .the bomb or other load comprises .two pincerlikejawmembers 24, 2*'5, pvoted upon .a common .axis 26 and cooperatingwhenapproached `together solas to Ybe capable of eng-agingabomb .shackleortho like, .the loop 21 of such shackle 'being sustained upon the tips.of;the.fiaws24, 25, which lare so spaced Iapart as to set uncertainforces tending to -separate them `when funderload. v'Ihe jaws 24, 25farerespectively provided with'pinoerglike extensions .having .co-

operating .plane .bearingvvfaces 24|, 25| (Figs. 2

and 3) arranged so that the insertion of a stop of roller form betweensuch faces retains the jaws 24, 25 in the closed position; said faces24|, 25|

are inclined to each other and the angle included between them soadjusted in accordance with surfaces. advantage of the frictional forcesset up- (a) It will be understood that by taking between the bombshackle 21 and the surfaces of the tips of the jaws 24, 25,'andl (b)between the jaws 24, 25 and their pivot Pin 2B, the ultimate ejectiveforce imposed upon the stop can be ref stricted to a degree such thatonly a comparatively light contrary force need be exerted to retain thestop in the locked position, and vthat such retaining force may be stillfurther geared down by the use of simple lever linkages in the lockingmechanism. y

In the arrangement which characteris'es the present invention,therefore, the majority o' the disengaging forces imposedby the load arebalanced by opposed reactions in the jaws 24, 25 through the roller-likestop 30, and only a suicient component of such disengaging forces isutilised for the provision of the stopejective force as will overcomethe friction between the stop and the jaw-faces. component Visdetermined by the inclination of vthe jaw-faces'to each other. Y,

The locking mechanism conveniently comprises a primary toggle linkage28, 290i which the end laterally about the pivot connecting it to thetoggle members 29, 3 I, the roller 30 being capable of slidingsufficiently between the surfaces 24|,

, 25| of the jaws 24, 25." Thus, any tendencies of Vthe load to movein aplane at right angles to the axis of the pivot pin 26 of the jaws arenot resisted by thek stop 30, and no force other than the light ejectiveforce acting upon therstop itself is'imposed upon the locking mechanism.

The attachmentmay be released mechanically by the impingement of aspring-pressed member 40 against, the'nger-piece 31.v Said member 40 isattached to the wedge-slide 20 so thatra movement of this member to theleft (as viewed in Figs. 2 and 3) under the pressure of the spring 23against the abutment shoulder 4|. would actuate the finger-piece 31 andrelease the toggles. To permit this action the stop 42 against which theslide 20 ordinarily abuts is made retractable, a cable 43 attached tosaid stop being operable so that by retractingsaid stop'42 ther pressureof the spring 23 causes the slide 20 to move as afore- The magnitudevofthis adjacent the jaw-members 24, 25 carries the aforesaid movable stop(which here consists ofa roller 30) engaged between the inclined faces24|, 25| of the jaw-members 24, 25,V the otherend of thev primary togglebeing anchored to a fixed pivot'. Linked to the central pivot of saidprimary toggle 28, 29 is one end of a secondary toggle 3|, 32 of whichthe other end isanchoredto a fixed pivot 33 whilst the link 3| isextended to form a catch 34 which is normally retained byV a trigger 35the resistance of which to the movement of the catch 34 is suilicient towithstand the ejective force imposed upon the movable stop 30 actingthrough the said toggle linkages 28, 29 and 3|, 32. The said trigger maybe released ,as desired by either mechanical or electro-magnetic means;appropriate forms of both mechanical and electro-magnetic release meansare hereinafter described. Both toggles are arranged to work only on therunway side of their dead centres, so that when'the trigger 35 isreleased the linkages are already free toA move towards their collapsedpositions illustrated by Fig. 3 un- Y der the ejective thrustimposedthrough the jaws 24, 25 upon the roller 3i); YA'suitable tensionspring 3S may be connected with the catch 34V in such manner as tocounteract Vits inertia and to assist in the actuation of thetoggleswhen the trigger 35 is released.

A nger-piece 31 may be connected to the catch 34 for the purpose ofre-cocking and releasing the toggle mechanism by hand.y If desired,theattachment may also include sel-cocki'ngmechanism arranged to comeinto operation automatically when the jaws are engaged with a load.

Fixed abutments 38, 39 are preferably provided in conjunction with thejaws 24, 25'for the purpose of absorbing Vfore-and-aft reactions imposedupon the attachment by possible swinging movements of the load. It'willV be Y'understood that the double-toggle mounting `ofthe movablestop 30 is such as to permit saidstop to move said, resulting in theshackle 21 of the bomb or :the like suspended from the jaws, 24,25,'being released. j Y

'A suitable form of electro-magnetic' release mechanism for theattachment, shown in Figs. 2 and 3, comprises a housing v44 enclosing anelectromagnet 45 capable of being energised as desiredjthrough a circuitwhich includes leads 46 'and `41 connected to two spring contacts (ofwhich one is shown at 48) fixed contacts 49 on the end-face of the slip(Fig. 5) and connections from said contacts to the magnet terminals at50. Associated with the magnet are two pivoted armatures 5|, 52 normallyheld in the open positionl by a common compression spring 53 whichpasses through the hollow centre ofthe magnet. The armature 5I has alever SII which, when the magnet isnotfenergised serves as an abutmentholding the armature 52 in theopen position. The armature 52 isoperatively connected with, or formed integrally with the trigger 35,and it will be seen that to permit the release of the trigger 35 it isnecessary when the magnet 45 is energised, for the armature 5| first tobe attracted towards it; this step removes the lever 5|| from itsposition holding the armature 52 which thereupon itself moves to theclosed position, as shown in Fig. 3.V Thus the trigger 35 is raisedfrom-engagement'with the catch'34 and the tog- `gle mech-anism isoperated to releaserthe jaws 2,4, 25. The double-check lever arrangementhere described for controlling the magnet armatures 5 I, 52 effectivelyserves to prevent the inadvertent release oi the trigger 35 by themovement of said vto closev the armature 52 and thus release., the

trigger 35,'such movement of the armature 52-is prevented by thepresence of the lever5H; a Vsimilar but oppositely directedV forcewhich-might tendtoY close the armature'5l is preventedlby the pressureof the springj53` for whichthe armaturev ,Y V52 and'trigger 35 thenserve asan abutment;

In case it is desired'for any? reason to prevent the inadvertent releaseof a load, the mechanism YcanV be locked'by `insertingra shapedstop 31|between the finger-piece 31 and a fixed part of the housing I6, as shownin Fig. 4; such stop-31| may veasily be withdrawn as soon asV it isrequired to release Athe load.

jBy reason of the arrangement whereby the reactive force exerted bytheload upon the attachment is utilised to release the jaws 24, 25 and alsoto operate the toggle mechanisms which lock said jaws in engagement, itwill be seen that the forces tending to release the jaws increase inproportion to the load. It is also an important feature of our improvedattachment that the frictional forces due to the load act to relieve therelease mechanism and not in opposition thereto as in certain knownforms of attachment; for this reason it is found unnecessary to payserious attention to the reduction of such friction between the workingparts of the attachment.

What we claim as our invention and desire to secure by Letters Patentis:

A releasable load-attaching device for aircraft and the like, comprisinga pair of load-gripping jaws pivoted on a common axis, opposed surfaceson said jaws adapted to receive therebetween a sto-p member, a movablestop member adapted to be engaged between said surfaces, means forlocking said stop member in engagement between said surfaces, said stopmember being movable with said surfaces upon common movement of saidjaws about said axis, and means for releasing said locking means, theangle between said surfaces when the jaws are in load-engaging relationbeing such as to impose a slight ejective force REGINALD KIRSHAWPIERSON. REGINALD ARTHUR FIRMAN.

REFERENCES CITED The following references are oi record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,346,022 Hassel July 6, 19201,481,259 Harrison Jan. 22, 1924 2,061,083 Niemi Nov. 17. 1936 2,064,547Laermann Dec. 15, 1936 2,416,028 Sloan Feb. 18, 1947

